Apparatus for positioning articles for application to objects

ABSTRACT

The invention provides apparatus for positioning articles for application to objects comprising a pair of jaws operable by cam means to open and close said jaws and a holder adapted to be pivoted from a position between said jaws when saiD jaws grip such an article passed to and held by said holder between said jaws upon operation of said cam means.

United States Patent Inventor David Stuart Cameron Loughborough, England Appl. No. 836,101 Filed June 24, 1969 Patented July 13, 1971 Assignee Charles Churchill Limited Nottingham, England Priority June 26, 1968 Great Britain 30,356/68 APPARATUS FOR POSITIONING ARTICLES FOR APPLICATION TO OBJECTS 4 Claims, 6 Drawing Figs.

US. Cl 144/32, 29/21 1 1323b 19/06 29/ 200,

[56} References Cited UNITED STATES PATENTS 2,689,589 9/1954 Allen et al. 144/32 3,187,405 6/1965 Rayburn 144/32 X 3,279,045 10/1966 Dixon 29/21 1 Primary Examiner-Donald R. Schran Altomey-Watson, Cole, Grindle & Watson ABSTRACT: The invention provides apparatus for positioning articles for application to objects comprising a pair of jaws operable by cam means to open and close said jaws and a holder adapted to be pivoted from a position between said jaws when saiD jaws grip such an article passed to and held by said holder between said jaws upon operation of said cam means.

PATENTEU JUL 1 3:911

SHEET 1 BF 4 LI V SHEET 2 OF 4 PATENTEUJUL13 IHYI PATENIED JULI awn sum u at 4 wJ L APPARATUS FOR POSITIONING ARTICLES FOR APPLICATION TO OBJECTS g This invention provides an applicator for automatic application to work of screws, nuts and like objects, comprising a pair of jaws, a pivoted holder movable intoposition between the jaws to receive in succession objects to be applied by the applicator, a cam controlling the jaws and normally maintaining them open, mechanism for shifting the cam to cause the jaws to close on an object held by the holder and thereafter moving the holder about its pivot to release the object, -means for thereafter moving the jaws to approach the object to the work and then causing the cam to reopen the jaws, and an applicator tool for applying the object to the work.v 1

Anautornatic screwdriver in accordance with the invention will now be described in detail, by way of example, with reference to theaccompanying drawings, in which:

FIG. 1 is a side' elevation of the apparatus,

FIG. '2 is a vertical section, the portion A of the H6. showing the upper part and the portion B -the lower part ofthe apparatus,

FIG. 3 is an end elevation, partly broken away, looking from the left-hand side of FIG. 2, portions A and B of the FIG. respectively showing the upper part and the lower part of the apparatus, I

FIG. 4 is a sectional view of the lower part of the apparatus, and

HG. Sis a section on the line V.V in FIG. 4.

The screwdriver illustrated in the drawings receives screws (FIG. 2) in succession from a chute 11, from which screws are discharged at regular intervals by an :escapement mechanism 12 which is described in detail in our copending British application No. 30356/68. Each screw 10,. when releaed by the escapement mechanism 12, is received and held by a forked holder 13 which engages the shank of the screw immediately below its head. The holder l3,is attached to the lower end of an arm 14 which is pivoted at 15 to the casing of the apparatus and normally held in the-position shown in H6. 2 by a spring 16.

Disposed on opposite sides of the holder 13 are jaws 17 adapted, when closed, to grip the shank of the screw 10. The jaws 17, the tips of which are at a level just below the holder 13, are pivoted at 18 (FIG. 3) to a sleeve 19 and are urged towards the closed position by springs 20. in the .position illustrated the jaws 17 are held open by a cam 21 which is slidably mounted on a tubular shaft 22 disposed within the sleeve 19 and, in the position shown in FIG. 2, rests on a circlip 42 on the lower end of the shaft 22. The shaft 22 is connected by a yoke 23 to the piston rod 24 of a pneumatic cylinder 25 and carries at its upper end a housing 26, attached to it by screws 27, which supports a pneumatic turbine 28. The drivenshaft 29 of the turbine 28 extends downwardly through the shaft 22 and carries a bit 34 at its lower end.

A compression spring 31 is disposed between a sleeve 32 on the upper end of the sleeve 19 and a collar 33 on the sleeve 19, and another compression spring 34' is disposed between the yoke 23 and the lower end of the sleeve 19. Bearings'25 are disposed between the shaft 22 and the sleeve 19. Upper and lower limit switches 36, 37 are provided and these switches are operated by an actuator 38 attached to the housing 26. A guide bar 39, carried by an arm 40 attached to the sleeve 19, extends through a hole in a fixed plate 4l.

in operation, after a screw 10 has been caught by theholder 13, air is admitted to the cylinder 25 to cause its piston to move downwardly and lower the shaft22, the spring 34 initially maintaining the sleeve 19 at its original leve Lowering of the circlip 42 upon descent of the shaft 22 permits the springs to squeeze the cam 21 into locating recesses 44 (Fig.1) in the jaws 17, which accordingly move inwardly to embrace the cam and grip the screw it). During the downwardi'tiovement of the shaft 22 a roller 45 (FIG. 2) on the yoke 23 engages a cam face 46 on the arm 14 to rock the cam counterclockwise about its pivot 15 against the action v 2 of the spring 16, so retracting the holder 13 and leaving the screw 10supported by the jaws 17.

After this, the undersurface of the housing 26 abuts the upper end of the sleeve 32 and, through the agency of the spring 31, continued downward movement of the shaft 22 imparts downward movement to the sleeve 19. The jaws 17, the

shaft 22, and the bit 30 move downwards in unison until the collar 33 on the sleeve 19 makes contact with 'an abutment 47 to arrest downward movement of the sleeve 19 and the jaws 17, continued downward movement of the shaft 22 compressing the spring 31. At the commencement of this last stage of downward movement of the shaft 22 the cam 21 is forced downwardly out of the recesses 44 in the jaws 17, so opening the jaws.

;During the first stage of downward movement of shaft 22, in

' which the jaws l7 close-as described above, the bit 30 is lowered to engage the screw and the turbine commences to rotate the shaft 29 and the bit 30 before the jaws 17 open. Whenthe jaws open the screw is positioned at the entrance of i 'the tapped hole into which it is to be screwed and the final descent of the bit 30 screws the screw home into the hole. The

downward'movement of the bit 30 ceases when-"the actuator 38 operates the lower limit switch 39. This reverses a valve in the pneumatic circuit'of-the cylinder 25,- causing the shaft 22 to move upwardly.

During upward movement of the shaft 22, the circlip 42 engages the undersurface of'the cam'21 to lift it and allow'the jaws 17 to close when the cam reaches a level opposite the recesses 44 in the jaws. In the initial stage of upward movement of the yoke 23 the spring 34 lifts the sleeve 19 and the jaws 17 so that the jaws are above the level of the head of the screw by the time they closc. The parts arefinally returned to the position illustrated and the cycle terminates when the actuator 38 operates the upper limit switch 36. This stops rotation of the turbine'28 and again reverses the pneumatic connections to the cylinder 25 to initiate a fresh cycle. During the upward movement the holder is returned by-the spring 16 to position to receive the next screw 10 discharged by the escapement mechanism 12 and the cam 21 is moved to the position of F l6. 4 with respect to the jaws 17 to open the latter prior to arrival of the next screw.

The holder 13 can also be utilized to receive and position nuts to be screwed on to male screw threads in which case the bit will be replaced by a blind female socket for rotating the nuts. The apparatus can also be utilized for-screwing bottle tops onto bottles.

- What I claim as my invention and desire to secure by Letters Patent is:

1. An apparatus for automatic application to work of screws, nuts and liketobjects, comprising a pair ofjaws, a

. pivoted holder movable into position between the jaws to 7 receive in succession objects to be applied by the applicator, a

cam controlling the jaws and normally maintaining them open, mechanismfor shifting the cam to cause the jaws to close on an object held by the holder and thereafter moving the holder about its pivot to release the object, means for thereafter moving the jaws to approach the object to the work and then causing the cam to reopen the jaws, and an applicator tool for applying the object to the work.

2. An applicator as claimed in claim 1, in which the applicator tool is a rotary bit for screwing into holes screws positioned by the jaws with respect to the holes.

3. Anapplicator as claimed in claim 1, which comprises a shaft extending between the jaws, the cam being. slidably mounted on'the shaft, a sleeve surrounding the shaft and carrying thev jaws, a motor for imparting downward movement to the shaft to cause the latter to entrain the cam and thereby shift it to open the jaws, means on the shaft for operating the holder to cause it to release the object, a lost-motion connection between the shaft and the sleeve which is effective to transmit downward movement from the shaft to -thesleeve after the jawshave closed and the holder has'released the-object and means. for arresting downward movement of the sleeve, when the object has been positioned by the jaws, and thereby cause further movement of the cam with respect to the jaws to open the jaws. 

1. An apparatus for automatic application to work of screws, nuts and like objects, comprising a pair of jaws, a pivoted holder movable into position between the jaws to receive in succession objects to be applied by the applicator, a cam controlling the jaws and normally maintaining them open, mechanism for shifting the cam to cause the jaws to close on an object held by the holder and thereafter moving the hoLder about its pivot to release the object, means for thereafter moving the jaws to approach the object to the work and then causing the cam to reopen the jaws, and an applicator tool for applying the object to the work.
 2. An applicator as claimed in claim 1, in which the applicator tool is a rotary bit for screwing into holes screws positioned by the jaws with respect to the holes.
 3. An applicator as claimed in claim 1, which comprises a shaft extending between the jaws, the cam being slidably mounted on the shaft, a sleeve surrounding the shaft and carrying the jaws, a motor for imparting downward movement to the shaft to cause the latter to entrain the cam and thereby shift it to open the jaws, means on the shaft for operating the holder to cause it to release the object, a lost-motion connection between the shaft and the sleeve which is effective to transmit downward movement from the shaft to the sleeve after the jaws have closed and the holder has released the object and means for arresting downward movement of the sleeve, when the object has been positioned by the jaws, and thereby cause further movement of the cam with respect to the jaws to open the jaws. . An applicator as claimed in claim 3, wherein the applicator tool is a rotary bit and which includes a pneumatic turbine for rotating the bit. 